The increasing miniaturization of electronic systems entails a continual reduction in the size of the electronic components required for them. Besides reduced structure widths, further measures are also taken to produce electronic components and circuit units, on which these components are arranged, in as compact a form as possible.
One important way of achieving this aim is to arrange a plurality of circuit units or silicon chips, also referred to as “dies”, in a single package, which may be made of plastic. In general, such silicon chips are then stacked one above the other, so that this arrangement is usually referred to as “stacked chips”. With such “stacked chips”, contact is conventionally made by virtue of it being necessary to route bonding wires from each connection pin on each chip to an externally routed contact and/or to a further chip, accommodated in the package.
Since demands on the signals to be transmitted being of parallel nature are continually rising, such contact among the circuit units within a conventional package is extremely disadvantageous. By way of example, signals in graphics memory units (graphics DRAM), digital signal processors (DSP) and processor chips or microprocessor circuit units need to be transmitted in highly parallel form, which means that the number of connection pins and of the bonding connections which are therefore necessary between circuit units in the package rises drastically. An increased number of bonding connections between the circuit units accommodated in the package inexpediently conflicts with the aim of miniaturizing the overall integrated circuit system which is accommodated in the package.
Another drawback is that a large number of bonding connections or bond wires gives rise to the possibility that these connections or wires will move and cause short circuits. In addition, an extremely high level of complexity and cost is involved in the method of manufacturing electronic systems in which a plurality of circuit units are accommodated in a package, with the circuit units being connected by bonding wires. Disadvantageously, this means that electronic systems based on the “stacked chips” principle cannot be produced in a package, or can be produced in a package only using a few circuit units.
Another proposal has been that contact between circuit units which are to be connected to one another be provided not just in one plane, i.e. in a contact plane, but rather three dimensionally.
Such a 3D contact system uses flexible circuit boards, for example, which can be designed three dimensionally in space in line with the contact requirements. However, the 3D contact systems have the drawback that they can firstly be manufactured only in complex fashion and give rise to a high level of cost. In addition, it is inexpediently impossible to provide a large number of parallel connections between circuit units, which is necessary for efficient data interchange in future electronic systems, solely using the 3D contact system.
FIG. 8 shows a conventional electronic circuit arrangement in which, by way of example, two circuit units 101a and 101b are accommodated in a package 100. The circuit units each have drivers and receivers for electrical signals. FIG. 8 also shows bonding wires or bond wires (bonding connections), which are conventionally necessary in order to provide data interchange between the circuit units 101a and 101b. It is thus obvious from a consideration of the electronic circuit arrangement illustrated in FIG. 8 that, in the case of relatively large scale integration, i.e. when a multiplicity of circuit units 101a-101n are provided in a single package 100, the bonding wires are extremely disadvantageous and conflict with miniaturization of the overall circuit arrangement.
It is therefore an object of the present invention to provide a circuit arrangement in which it is' possible to accommodate a large number of circuit units in a package in space saving fashion, avoiding the drawbacks of the prior art which are brought about as a result of the connections among the circuit units.